Permanent Raised Bed Gardening: Plastic Mulch Application

Plastic mulch applied to a recycled auto tire bed using the lath technique	"Rolling out" mulch film
Use a minimum of four pieces of lath to attach mulch film to the end of bed.	Placement of lath on frame between stakes

To remove the film, back the hex head screws out of the pockets until the lath pieces are released. Collect the lath pieces and store them in a dry location to prevent warping. Dispose of the mulch film in a responsible manner. Leave the hex head screws in the pockets where they will be ready for service the next time film is applied.

Applying plastic mulch to a corrugated sheet metal bed using the lath technique is similar to an auto tire bed with a few differences.

Begin by unrolling the mulch film using one of the two methods previosly described.

Attach the free end of the film to the end of the bed using the lath pieces. Working with one piece of lath at a time, wrap the film around the lath, pull the film over the top of the bed and attach the lath to the side of the 2-inch by 4-inch frame using 1-inch hex head screws. Space the lath pieces 1 foot apart.

Proceed to the other end of the bed. Cut the film from the roll, leaving an extra foot of film to work with. Repeat the fastening process on this end. As you roll the film around the lath, pull the film towards you to remove any slack. Don't overstretch the film because tearing could occur.

Using the same lath technique, attach film to both sides of the beds, stretching the film crossways to remove any slack prior to attaching. Attach the film to the portion of the wood frame located between the sucker rod stakes.

A helpful tip when applying mulch on a windy day: if at all possible, walk with the wind while unrolling the film, keeping the film as low as possible. The first time the mulch goes airborne, you'll appreciate the advice.

Depending on how you've configured the drip irrigation, you possibly will need to cut a hole in the mulch to accept the drip supply line feeding one end of the beds.

After removing the plastic mulch, collect the hex head screws or simply reinsert them into the wood frame. Remember to store the wood lath in a dry place when it's not in use.

A few closing comments on the use of mulch film. While black plastic mulch is recommended for use on spring planted crops, problems can arise if used in conjunction with summer plantings. In the southern U.S., the extreme heat generated with the use of black plastic mulch exerts tremendous stress on young seedlings.

During summer months, some growers substitute white or silver-colored mulch for black. These lighter colored films are more efficient in reflecting sunlight, thus preventing excessive heat buildup in the beds. They are commonly used for establishing such crops as fall tomatoes or cole (cabbage, broccoli, etc.) crops under hot summer conditions.

Organic materials offer an effective alternative to plastic for summer mulching. At the Noble Foundation, we mulch all of our summer plantings with compost. Summer use of organic mulch offers all the advantages common to plastic mulch, plus it constitutes a source of slow-release fertilizer. When incorporated into the soil, organic mulch increases the water and nutrient holding capacity of the soil and improves soil tilth.